The C282Y mutation was not found among the infertile/subfertile men or the fertile controls. Genotype frequencies of the H63D mutation among the different groups of infertile men and fertile controls are given in Table 1. The frequencies of H63D heterozygotes and homozygotes for infertile/subfertile men were 25.4 and 1.0%, respectively, and for fertile controls 23.4 and 0.7%, respec­tively. However, when analyzed in different groups of infertile men according to their sperm counts, a borderline significance was obtained for the frequencies of H63D heterozygotes and homozygotes in severe oligozoospermic subjects (41.2 and 2.9%, respectively), when compared to those of the fertile controls (p = 0.049).